The larva of the gall midge Rabdophaga salicis forms galls on certain  Sallow and Willow species (Salix sp.) including Creeping Willow, Eared Willow, Grey Willow and Goat Willow. The gall is a smooth, globular or spindle-shaped swelling, usually on a twig or stem, sometimes several together and sometimes coalescing. 

The galls contain several larvae or pupae in separate chambers. The galls are usually at least 5mm wide and the larvae feed on the pith inside the gall. The gall occasionally occurs on the petiole, midrib, or side veins of a leaf.

Several other species of Rabdophaga form similar galls on Sallows and Willows.  

An Agromyzid fly, several sawflies (Euura species), beetles and moths also form galls in twigs and stems of Sallows and Willows; these are generally woody 

Gall Adult

Open the gall to check for midge larvae.  Ensure you have identified the willow or sallow correctly and note the species in your comments. There is guidance here:  https://www.naturespot.org/family/salicaceae

Wherever the host willow species occur, usually in damper areas.

Galls are usually encountered on late summer or early autumn.

Galls contain pale orange larvae.

Widespread in Britain, though not particularly well recorded.

Status in Leicestershire and Rutland not known.